Journal ArticleDOI
Polymorphic Behavior of Thin Evaporated Films of Zirconium and Hafnium Oxides
TLDR
In this article, thin evaporated films of zirconium and hafnium oxides were investigated from 100° to 1500°C by electron diffraction and transmission electron microscopy.Abstract:
Polymorphism in thin evaporated films of zirconium and hafnium oxides was investigated from 100° to 1500°C by electron diffraction and transmission electron microscopy. The films have metastable cubic structures at room temperature and at moderate temperatures. Zirconium oxide, depending on temperature, exists in cubic, tetragonal, and monoclinic forms, whereas hafnium oxide transforms directly from the cubic to the monoclinic structure. The transformation temperatures depend on the oxygen partial pressure. Air annealing of thin films of ZrO2 and HfO2 lowered the temperature of transformation of the tetragonal and the cubic structure into the monoclinic structure by about 150° and 100°C, respectively. The cubic/tetragonal transformation of ZrO2 is monotropic, whereas the tetragonal monoclinic transformation occurs by the typical nucleation and growth mechanism. Determination of grain size in ZrO2 at the tetragonal/monoclinic transformation temperature showed that the transformation occurs when a constant grain size of about 800 A is reached. The oxygen partial pressure, grain size, and temperatures at which the metastable phases exist were correlated. The rate of grain growth is enhanced by increase in oxygen partial pressure. The accelerated transformation in air is attributed to rapid attainment of the critical size; grain boundary energy is an important controlling factor in transformation.read more
Citations
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The origin of ferroelectricity in Hf1−xZrxO2: A computational investigation and a surface energy model
TL;DR: In this paper, the structural, thermal, and dielectric properties of the ferroelectric phase of HfO2, ZrO2 and Hf0.5O2 are investigated with carefully validated density functional computations.
Journal ArticleDOI
Criteria for bombardment-induced structural changes in non-metallic solids
H. M. Naguib,Roger Kelly +1 more
TL;DR: In this article, both a temperature-ratio and a bond-type criterion are used to predict the occurrence of amorphization or crystallization in non-metallic solids induced by energetic heavy ions.
Journal ArticleDOI
Hafnia and hafnia-toughened ceramics
J. Wang,H. P. Li,R. Stevens +2 more
TL;DR: In this article, a review of the science and technology of HfO2 and hafnium-based materials in terms of processing, phase transformation, microstructure, and mechanical properties is presented.
Journal ArticleDOI
The Origin of Ferroelectricity in Hf$_{x}$ Zr$_{1-x}$ O$_2$: A Computational Investigation and a Surface Energy Model
TL;DR: In this article, the structural, thermal, and dielectric properties of the ferroelectric phase of HfO$_2, ZrO_2$ and Hf$_{0.5}$ Zr$_{1-\chi}$ O$-2$ (HZO) are investigated with carefully validated density functional computations.
Journal ArticleDOI
Characterization and Stabilization of Metastable Tetragonal ZrO2
TL;DR: In this paper, single-domain and polydomain particles of tetragonal ZrO2 were prepared by hydrothermal and heat treatment of Zr O2·nH2O.
References
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Journal ArticleDOI
Nature and Thermal Evolution of Amorphous Hvdrated Zirconium Oxide
J. Li Vage,K. Doi,C. Mazieres +2 more
TL;DR: In this paper, the thermal behavior of amorphous hydrated zirconium oxide and its coprecipitates with other oxides was studied and a relation with the high-temperature solid solution was established.
Journal ArticleDOI
Metastable Transitions of Zirconium Oxide Obtained from Decomposition of Alkoxides
Journal ArticleDOI
Kinetics and mechanism of the transition of metastable tetragonal to monoclinic zirconia
Journal ArticleDOI
Chemistry of Zirconium Dioxide X-Ray Diffraction Studies
G. L. Clark,D. H. Reynolds +1 more